The invention relates to a transmitter system for a Ferraris motion transmitter, wherein one or several magnetic field generators together with a moving, electrically conducting rotating measuring body form at least one magnetic measurement assembly, whereby output signals can be generated by magnetic field sensors coupled thereto, the output signals depending on the rotation speed or rotation acceleration. Such transmitter systems on known, for example, from the publication “Aufnehmer zur Messung schnell veränderlicher Drehbeschleunigungen und Drehmomente” (Sensor for measuring rapidly changing rotation accelerations and torques), A. Denne, H. Rausch and W. Freise, Technisches Messen 48th year 1981, Vol. 10, pages 339 to 342. The rotating measuring body is herein implemented as a drag cup. Another transmitter system of this type is known from DE 37 30 841 A1, wherein the rotating measuring body is a disk. If such transmitter systems are to be used to measure the rotation speed or rotation acceleration of a motor, preferably of an electric motor, then the measuring body that is specifically adapted to the transmitter system always has to be attached to the shaft.
Not only the measuring body therefore represents a specific component, but a specifically adapted joining technique with the corresponding device shaft is also required. The connection between the measuring body and the shaft can hereby cause erroneous measurement results if the stiffness is insufficient. A potential play between the rotating measuring body and the stationery components of the transmitter system also has to be taken into consideration with conventional solutions. Such play can be caused, for example, in that the symmetry axis of the measuring body cannot be brought into exact alignment with the shaft and/or that the measuring body is not completely rotationally symmetric.
Any existing play can adversely affect the distance, so that the distance cannot be made arbitrarily small and larger overall geometric dimensions of the system has to be accepted. This also results in longer time constants and hence a poorer dynamic characteristic. A larger distance also reduces the sensitivity of the sensor.